$ 780 \div (5 \div -4) $
$ = 780 \times (-4 \div 5)$ $ = (780 \times -4) \div 5$ $ = -3120 \div 5$ ${5}$ ${3}$ ${1}$ ${2}$ ${0}$ $\text{Bring the decimal up into the}$ $\text{answer (the quotient).}$ ${3}$ $\text{How many times does }5\text{ go into }{3}\text{?}$ ${0}$ ${3}$ $-\vphantom{0}$ ${3}\div5={0}\text{ or }5\times{0} = {0}$ ${1}$ $\text{How many times does }5\text{ go into }{31}\text{?}$ ${6}$ ${3}$ ${0}$ ${1}$ $-\vphantom{0}$ ${31}\div5={6}\text{ or }5\times{6} = {30}$ ${2}$ $\text{How many times does }5\text{ go into }{12}\text{?}$ ${2}$ ${1}$ ${0}$ ${2}$ $-\vphantom{0}$ ${12}\div5={2}\text{ or }5\times{2} = {10}$ ${0}$ $\text{How many times does }5\text{ go into }{20}\text{?}$ ${4}$ ${2}$ ${0}$ ${0}$ $-\vphantom{0}$ ${20}\div5={4}\text{ or }5\times{4} = {20}$ A negative number divided by a positive number is a negative number. $-3120 \div 5 = -624$